[Elecraft] Filter questions

[W5UN]

Elecraft believes the 250 hz filter problem is a defective filter, 
and is sending a new replacement..

Bill, does your  CW Skimmer signals stay right on frequency as you 
switch filters (as happens automatically with changing  DSP width 
when filters are enabled)?

Dave, W5UN

At 23:03 11/17/2008, you wrote:



>Dave Blaschke wrote:
> >
> > I will ask here before calling Elecraft.
> >
> > First, I have the following filters installed on the main rcvr, all 8
> > pole: 6 Khz, 2.8kHz, 1.8 kHz, 400 Hz, 250 Hz.
> >
> > There are two issues:
> >
> > 1. When I turn my 250 Hz filter on in config, and then select that
> > filter (which is FL5 here)I can hear noise coming through but no cw
> > signals come through. I can see the signals on my PowerSDR/LP-PAN
> > setup and CW Skimmer. Signal comes through all the rest of the
> > filters O.K. Yes, I opened the radio, and all the filters are installed.
> >
> > 2. I run CW Skimmer with my K3. When I change filters, the CW offset
> > signal shown on CW Skimmer changes. I thought the 8 pole filters had
> > no offset. Is anyone else experiencing this? Any comment appreciated.
> >
> > Dave, W5UN
> >
>
>Both issues sound like there could be an offset problem in the 250 Hz
>filters.  I only have 5-pole CW filters here but I know Ed W0YK has reported
>offsets in his 8-pole 400/250s of up to 80 Hz.  Given that the 250 Hz 8-pole
>is actually around 370 Hz wide according to Inrad plots, I don't see how
>even an 80 Hz offset could cause the problem you noted in #1 above.  However
>I believe most of the 8-pole filters will have the problem in #2 above since
>they do not truly have zero offset.
>
>If I used 8-pole CW filters, I would measure the actual offset and enter it
>into the Filter Configuration menu.  This would solve problem #2 above and
>it might also tell you whether you have a defective 250 Hz filter causing #1
>above.
>
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>
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